Titania-metal composite and method for preparation thereof, and film forming method using dispersion comprising the composite

ABSTRACT

Under the presence of at least one out of copper, manganese, nickel, cobalt, iron, zinc, and compounds thereof, a tetravalent titanium salt solution and a basic solution are reacted together to form a hydroxide of titanium and the above metal, and then the titanium hydroxide is peroxidated with an oxidizing agent to manufacture an aqueous liquid or dispersion having therein titanium oxide fine particles having peroxy groups; by using this alone to form a coating film adjacent to a coating film of an organic dye or pigment, or using this to form a coating film together with an organic dye or pigment, a drop in decorativeness of color due to fading or discoloration of a coating material, a printed article, a building material, a fiber, an organic polymer resin product or the like can be prevented, and moreover surface anti-soiling and hydrophilic properties can be realized.

TECHNICAL FIELD

The present invention relates to a titania-metal composite able tosuppress or reduce discoloration or fading caused by an organic materialsuch as a resin or an organic dye undergoing photooxidation throughsunlight or the like, and a method of manufacturing the titania-metalcomposite.

Moreover, the present invention relates to a film formation method forforming a coating film on a substrate comprising an inorganic or organicmaterial using an aqueous liquid or dispersion containing thetitania-metal composite.

Furthermore, the present invention relates to a film formation methodfor forming a hydrophilic coating film having a self-cleaning functionof removing soiling such as oil on the surface of a substrate comprisingeither an organic or inorganic material.

BACKGROUND ART

From hitherto, fading and discoloration of colored decorative coatingfilms and the like formed on any of various substrates (e.g. printedarticles, building materials, fibers, organic polymer resin products,etc.) using organic dyes and pigments has been a problem. Factors insuch color degradation include photooxidation, photoreduction andthermal reactions, and various methods have been thought of ascountermeasures.

For example, to prevent degradation of an organic dye or pigment or thesurface of an organic polymer resin sheet, methods have been adoptedsuch as mixing into the material an ultraviolet absorber that absorbsenergy that will bring about photooxidation, or forming anoxidation-preventing film on the surface of the substrate.

Moreover, removing soiling such as oil on the surface of any of varioussubstrates comprising either an organic or inorganic material requireseffort, and hence methods of forming a coating film having ananti-soiling function or a self-cleaning function have been developed.As such a method, for example substrates that make use of aphotocatalytic function using anatase-type titanium oxide developed bythe present inventors have received attention.

However, an aqueous liquid or dispersion containing anatase-typetitanium oxide developed by the present inventors contains not onlytitanium peroxide having a photocatalytic function, but also any ofvarious metal compounds of copper, tin, iron, zinc, indium, silver,calcium, aluminum, nickel, silicon, selenium or the like, and hence inthe case of using such an aqueous liquid or dispersion with an organicmaterial such as a resin or an organic dye, degradation such asdiscoloration or fading through sunlight or the like has beenunavoidable.

Moreover, as a film formation method that aims only for a substratesurface self-cleaning effect, art is known in which a film of silica ora silica compound is formed on the substrate, thus making the substratesurface hydrophilic so that soiling can be removed using running water.

However, a surface on which a film of anatase-type titanium oxide or thelike having a photocatalytic function has been formed has strongadsorptivity, and hence adsorbs substances that are to be subjected tosoiling decomposition, and then these substances are decomposed by theexcitation wavelength of sunlight or the like. Application of such filmformation to an inorganic substrate is relatively easy, but withapplication to an organic substrate, degradation is brought aboutthrough decomposition of the organic substrate surface, and hence thishas been coped with by forming a primer as a first layer and then aphotocatalytic film as a second layer. Consequently, it has beenimpossible to attain both prevention of degradation caused byphotooxidation of the organic substrate and an anti-soiling functionusing photocatalysis, with these inherently running counter to oneanother.

DISCLOSURE OF THE INVENTION

It is a first object of the present invention to provide a titania-metalcomposite able to reduce molecular bond dissociation of organic materialdue to sunlight, any of various types of electromagnetic radiation orthe like, and a method of manufacturing the titania-metal composite.

It is a second object of the present invention to provide a filmformation method using a dispersion of a titania-metal composite asabove, and any of various substrates having a coating film containing atitania-metal composite as above formed thereon using the film formationmethod.

It is a third object of the present invention to provide a titania-metalcomposite that, upon forming a film thereof on the surface of asubstrate that may be inorganic or organic, prevents photooxidativedegradation of the substrate surface and color fading that would mar thedecorativeness of the substrate surface, and has a self-cleaningfunction of removing soiling on the surface on which the film is formed,and a method of manufacturing the titania-metal composite, and also afilm formation method using a dispersion of the titania-metal composite,and any of various substrates having a coating film containing thetitania-metal composite formed thereon using the film formation method.

In the process of research and development into aqueous liquidscontaining titanium peroxide having a photocatalytic function doped withany of various metal compounds of copper, tin, iron, zinc, indium,silver, calcium, aluminum, nickel, silicon, selenium or the like, thepresent inventors have discovered that in the case of using an aqueousliquid containing titanium peroxide doped with a specific metal or acompound thereof on an organic material such as a resin or an organicdye, performance degradation such as discoloration or fading caused bysunlight or the like, and photocatalytic oxidative decomposition can beavoided.

That is, the present invention provides a composite between metallicmanganese, iron, cobalt, nickel, copper or zinc or a compound thereofand anatase-type, brookite-type or rutile-type titanium dioxide having aphotocatalytic activity or amorphous-type titanium dioxide not having aphotocatalytic activity, and a method of manufacturing such a composite.

By adding such a metal or compound thereof, it becomes such that thephotocatalytic activity is no longer exhibited, or in the case of acomposite with amorphous-type titanium dioxide, even if the composite isheated to convert the crystalline form into the anatase type,photocatalytic activity will not arise. On the other hand, with adispersion containing the titania-metal composite, there is an effectthat even if the dispersion has water or an organic solvent such as analcohol as a solvent therein or is a paint containing an organic polymerresin, degradation of the paint film after painting is prevented, andmoreover degradation of the painted substrate and fading of an organicdye or pigment are prevented, i.e. degradation due to photooxidationcaused by sunlight, fluorescent light or any of various types ofelectromagnetic radiation is reduced.

Moreover, the present invention provides a method of manufacturing atitania-metal composite, this method characterized by reacting atetravalent titanium salt solution and a basic solution together underthe presence of at least one out of copper, manganese, nickel, cobalt,iron, zinc, and compounds thereof to form a hydroxide of titanium andthis metal, and then peroxidating the titanium hydroxide with anoxidizing agent, whereby the titanium oxide in the aqueous liquid isdoped with at least one metal compound.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram showing the outline of an example of a method ofmanufacturing a titania-metal composite according to the presentinvention.

FIG. 2 consists of drawings showing examples in which a dispersioncontaining a titania-metal composite according to the present inventionis applied to an organic material substrate surface.

FIG. 3 consists of drawings showing various modes for forming a coatingfilm having excellent organic dye/pigment degradation-preventingperformance using a dispersion containing a titania-metal compositeaccording to the present invention.

FIG. 4 consists of drawings showing various modes of an organic materialstructure or a structure having an organic material coating film havingexcellent degradation prevention performance under the presence of acoating film having a photocatalytic function.

FIG. 5 is a bar chart showing the color persistence of sample substrates(sample substrates 6 to 10 and comparative substrate 2) according to theresults of evaluation test 2.

FIG. 6 is a bar chart showing the color persistence of sample substrates(sample substrates 6′ to 10′ and comparative substrate 2′) according tothe results of evaluation test 2.

FIG. 7 is a bar chart showing the color persistence of sample substrates(sample substrates 11 to 16 and comparative substrate 3) according tothe results of evaluation test 3.

FIG. 8 is a drawing showing a film-forming sample substrate used in‘working example 8’.

BEST MODE FOR CARRYING OUT THE INVENTION (A) First Invention:Titania-Metal Composite and Method of Manufacturing the Same (A-1)Titania-Metal Composite

A titania-metal composite according to the present invention containstitanium oxide fine particles having peroxy groups, coexisting with atleast one out of copper, manganese, nickel, cobalt, iron, zinc, andcompounds thereof; the nature of the titania-metal composite is fineparticles or a powder. Moreover, an aqueous liquid or dispersion of thetitania-metal composite is prepared by reacting a tetravalent titaniumsalt solution and a basic solution together under the presence of atleast one out of copper, manganese, nickel, cobalt, iron, zinc, andcompounds thereof to form a hydroxide of titanium and this metal, andthen peroxidating the titanium hydroxide with an oxidizing agent. Thetitanium oxide fine particles having peroxy groups contained in theaqueous liquid or dispersion may be either amorphous-type oranatase-type, or both of these may be present mixed together.

That is, with a composite between metallic manganese, iron, cobalt,nickel, copper or zinc, which come after vanadium and chromium, whichcome after Ti in terms of atomic number, or a compound thereof, andanatase-type, brookite-type or rutile-type titanium dioxide havingphotocatalytic activity or amorphous-type titanium dioxide not havingphotocatalytic activity, by adding the metal compound, it becomes suchthat the photocatalytic activity is no longer exhibited, or in the caseof a composite with amorphous-type titanium dioxide, even if thecomposite is heated to convert the crystalline form into the anatasetype, photocatalytic activity will not arise.

It is thought that these phenomena arise through the potentialdifference between the composited metals. As a result, with a dispersioncontaining the titania-metal composite, there is an effect that even ifthe dispersion has water or an organic solvent such as an alcohol as asolvent therein or is a paint containing an organic polymer resin,degradation of the paint film itself after painting is prevented, andmoreover degradation of the painted substrate and fading of an organicdye or pigment are prevented, i.e. degradation due to photooxidationcaused by sunlight, fluorescent light or any of various types ofelectromagnetic radiation is reduced.

(A-2) Method of Manufacturing Titania-Metal Composite

As a method of manufacturing a titania-metal composite according to thepresent invention, a manufacturing method using a hydrochloric acidmethod or a sulfuric acid method, these being common methods ofmanufacturing a titanium dioxide powder, may be used, or a manufacturingmethod using any of various liquid-dispersed titania solutions may beused. The above-mentioned metal or compound thereof can be composited ineither before or after peroxidating the titania dispersion, which may beof any of various types as described below. Examples of the method are asol-gel method known from hitherto, and the following three methods.

(A-2-1) First Manufacturing Method

A tetravalent titanium salt solution and an ammonia aqueous solution arereacted together to form a titanium hydroxide, this hydroxide isperoxidated with an oxidizing agent to form ultra-fine particles ofamorphous-type titanium peroxide, and heating treatment is furthercarried out to convert into anatase-type titanium peroxide; in one ofthese processes, a metal or compound thereof as described above is mixedin.

(A-2-2) Second Manufacturing Method

A tetravalent titanium salt solution is peroxidated, the peroxidatedtetravalent titanium salt solution is reacted with an ammonia aqueoussolution to form a hydroxide and thus form ultra-fine particles ofamorphous-type titanium peroxide, and heating treatment is furthercarried out to convert into anatase-type titanium peroxide; in one ofthese processes, a metal or compound thereof as described above is mixedin.

(A-2-3) Third Manufacturing Method

A tetravalent titanium powder or titanium oxide powder, hydrogenperoxide, and an ammonia aqueous solution are reacted together to carryout titanium hydroxide formation and peroxidation simultaneously andthus form ultra-fine particles of amorphous-type titanium peroxide, andheating treatment is further carried out to convert into anatase-typetitanium peroxide; in one of these processes, a metal or compoundthereof as described above is mixed in.

Note that through the peroxidation with the oxidizing agent,amorphous-type titanium peroxide is formed, and it goes without sayingthat this can be used as the titania-metal composite aqueous liquid ordispersion of the present invention. Moreover, if this is heated, thetitanium is converted into the anatase type, and it goes without sayingthat this can also be used as the aqueous liquid or dispersion of thepresent invention.

(A-2-4) Manufacturing Method Using Sol-Gel Method

A solvent such as water or an alcohol, and an acid or basic catalyst aremixed and stirred with a titanium alkoxide to hydrolyze the titaniumalkoxide. As a result, a sol solution of titanium oxide ultra-fineparticles is produced. A metal or compound thereof as described above ismixed in before or after the hydrolysis. Note that the titanium oxideobtained in this way is amorphous-type modified with peroxy groups.

As the titanium alkoxide, a compound represented by the general formulaTi(OR′)₄ (wherein R′ is an alkyl group), or a compound in which one ortwo of the alkoxide groups (OR′) in this general formula have beensubstituted with carboxyl groups or β-dicarbonyl groups, or a mixturethereof is preferable.

Specific examples of the titanium alkoxide include Ti(O-iso-C₃H₇)₄,Ti(O-n-C₄H₉)₄, Ti(O—CH₂CH(C₂H₅)C₄H₉), Ti(O—C₁₇H₃₅)₄,Ti(O-iso-C₃H₇)₂[CO(CH₃)CHCOCH₃]₂, Ti(O-nC₄H₉)₂[OC₂H₄N(C₂H₄OH)₂]₂,Ti(OH)₂[OCH(CH₃)COOH]₂, Ti(O—CH₂CH(C₂H₅)CH(OH)C₃H₇)₄ and Ti(O-nC₄H₉)₂[OCOC₁₇H₃₅].

(A-3) Regarding the First Manufacturing Method

Next, a detailed description will be given of the first manufacturingmethod. As shown in FIG. 1, a solution of a tetravalent titanium saltsuch as titanium tetrachloride and a basic solution such as ammoniawater are mixed together in the presence of at least one out of copper,manganese, nickel, cobalt, iron, zinc, and compounds thereof, thusreacting the tetravalent titanium salt and the basic solution together,and hence producing a hydroxide of the metal and a hydroxide oftitanium.

Here, there are no particular limitations on the concentration ortemperature of the reaction solution, but it is preferable to carry outthe reaction with a dilute solution at ambient temperature. The reactionis a neutralization reaction, and hence it is preferable to adjust fromacidic to neutral, i.e. to pH 7. If the hydroxide obtained in this wayis washed with pure water, and then peroxidated with a hydrogen peroxideaqueous solution, then an aqueous liquid or dispersion containingamorphous-type titanium oxide fine particles having peroxy groups, i.e.an aqueous liquid or dispersion containing a titania-metal compositeaccording to the present invention, can be manufactured.

Hydrogen peroxide is preferable as the oxidizing agent when carrying outthe peroxidation, and there are no particular limitations on theconcentration thereof, although 30 to 40% is preferable. Note that theoxidizing agent is not limited to being hydrogen peroxide, but rather,as described earlier, any of various oxidizing agents can be used solong as a peroxide of titanium can be formed. As described above, uponmixing titanium hydroxide and hydrogen peroxide together, a peroxidationreaction gradually proceeds, and a dispersion of amorphous-type titaniumperoxide is formed. It is preferable to cool before carrying out thisoxidation. Here, it is preferable to carry out the cooling such that thetemperature of the titanium hydroxide becomes 1 to 5° C.

(A-4) Tetravalent Titanium Salt

As the tetravalent titanium salt used in the manufacture of thetitania-metal composite aqueous liquid or dispersion according to thepresent invention, any of various titanium compounds can be used so longas a gel of titanium hydroxide, also known as ortho-titanic acid(H₄TiO₄), can be formed upon reacting with a basic solution such asammonia water or a sodium hydroxide solution; examples are water-solubleinorganic acid salts of titanium such as titanium tetrachloride,titanium sulfate, titanium nitrate and titanium phosphate. Otherexamples are water-soluble organic acid salts such as titanium oxalate.Out of these various titanium compounds, titanium tetrachloride ispreferable from the standpoints of the water solubility beingparticularly good, and components other than titanium in the titaniumcompound not remaining in the coating film-forming aqueous liquid ordispersion manufactured.

Moreover, there are no particular limitations on the concentration ofthe tetravalent titanium salt solution so long as the concentrationduring reaction is within a range such that a gel of titanium hydroxidecan be formed, but a relatively dilute solution is preferable.Specifically, the concentration of the tetravalent titanium saltsolution is preferably 5 to 0.01 wt %, more preferably 0.9 to 0.3 wt %.

(A-5) Basic Solution

Moreover, as the basic solution reacted with the tetravalent titaniumsalt solution, any of various ones can be used so long as a gel oftitanium hydroxide can be formed upon reaction with the tetravalenttitanium salt solution; examples include ammonia water, a sodiumhydroxide aqueous solution, a sodium carbonate aqueous solution, and apotassium hydroxide aqueous solution, with ammonia water beingpreferable.

Moreover, there are no particular limitations on the concentration ofthe basic solution so long as the concentration during reaction iswithin a range such that a gel of titanium hydroxide can be formed, buta relatively dilute solution is preferable. Specifically, theconcentration of the basic solution is preferably 10 to 0.01 wt %, morepreferably 1.0 to 0.1 wt %. In particular, the concentration in the caseof using ammonia as the basic solution is preferably 10 to 0.01 wt %,more preferably 1.0 to 0.1 wt %.

(A-6) Oxidizing Agent

As the oxidizing agent for subsequently oxidizing the titanium hydroxideformed, any of various oxidizing agents can be used without limitationso long as a peroxide can be formed through the oxidation; hydrogenperoxide is preferable since residual matter such as metal ions or acidions will not arise in the coating film-forming liquid manufactured.

(A-7) Doped Metal Compound

Examples of compounds of copper, manganese, nickel, cobalt, iron andzinc respectively that may be made to coexist with the solution of thetetravalent titanium salt such as titanium tetrachloride are as follows.

Ni compounds: Ni(OH)₂, NiCl₂Co compounds: Co(OH)NO₃, Co(OH)₂, CoSO₄, CoCl₂Cu compounds: Cu(OH)₂/Cu(NO₃)₂/CuSO₄, CuCl₂, Cu(CH₃COO)₂Mn compounds: MnNO₃, MnSO₄, MnCl₂Fe compounds: Fe(OH)₂/Fe(OH)₃, FeCl₃Zn compounds: Zn(NO₃)₂, ZnSO₄, ZuCl₂

The concentration of the titanium peroxide in the aqueous liquid ordispersion (the total amount including coexisting compounds of copper,manganese, nickel, cobalt, iron or zinc) is preferably 0.05 to 15 wt %,more preferably 0.1 to 5 wt %. Moreover, regarding the content of the atleast one out of copper, manganese, nickel, cobalt, iron, zinc, andcompounds thereof, the molar ratio between the titanium and this metalcomponent is preferably in a range of 1:0.01 to 1:0.5, more preferably1:0.03 to 1:0.1.

(A-8) Effects of Using Titania-Metal Composite

With a substrate having formed thereon a film of titania doped with atleast one out of copper, manganese, nickel, cobalt, iron, zinc, andcompounds thereof according to the present invention, the promotion ofoxidative degradation of the substrate surface caused by ultravioletradiation (sunlight) or short-wavelength electromagnetic radiation thatcauses photooxidation can be prevented or reduced.

With such photooxidation, it is said that .OH (hydroxyl radicals) or ¹O₂(singlet oxygens) are produced from oxygen or moisture in the air ororganic matter through electromagnetic radiation, and cause oxidativedegradation inside or on the outside of the substrate.

The titania-metal composite according to the present invention is ableto stabilize the unstable active state of such radicals, wherebyphotooxidative degradation of the surface of a substrate comprising anorganic material or an inorganic material by ultraviolet radiation(sunlight) or radical-producing electromagnetic radiation can beprevented or reduced, and degradation of an organic resin, colordegradation (fading) or substrate degradation can be prevented, andoxidative degradation of the surface of an inorganic material can bereduced.

(B) Second Invention: Film Formation Method (Organic Material Structure)Using Aqueous Liquid or Dispersion as Described Above (B-1) FilmFormation Method Using Titania-Metal Composite Aqueous Liquid orDispersion

An organic material structure according to the present invention has acoating film containing titanium oxide fine particles doped with atleast one out of copper, manganese, nickel, cobalt, iron, zinc, andcompounds thereof (a titania-metal composite) on a surface thereof, orhas such particles dispersed therein.

As shown in FIGS. 2A and B, the former can be manufactured by buildingup a layer of an aqueous liquid or dispersion containing a titania-metalcomposite as described in (A) above onto, or permeating such an aqueousliquid or dispersion into, the surface of an organic material substrate.Moreover, as shown in FIG. 2C, the latter can be manufactured bydispersing an aqueous liquid or dispersion containing a titania-metalcomposite as described in (A) above into an organic material, and thenmolding into a desired shape.

(B-2) Film Formation Method Having Function of Preventing Fading orDegradative Discoloration of Organic Material

By using an aqueous liquid or dispersion containing a titania-metalcomposite as described in (A) above in one of the undermentioned modes,fading of an organic dye or pigment caused by ultraviolet radiation orthe like, or degradative discoloration of an organic material can besuppressed. Note that the undermentioned modes are illustrated in FIG.3.

(1) A titania-metal composite aqueous liquid or dispersion is mixed withan organic dye or pigment or an organic polymer resin containing anorganic dye or pigment, and a coating film is formed on a substratesurface.

(2) A coating film of a titania-metal composite aqueous liquid ordispersion according to the present invention (hereinafter referred toas a ‘degradation-preventing coating film’) is formed on a substratesurface, and then a coating film of an organic dye or pigment or anorganic polymer resin containing an organic dye or pigment is formed onthe surface (FIG. 3A).

(3) Two types of degradation-preventing coating films are formed on asubstrate surface, and then a coating film of an organic dye or pigmentor an organic polymer resin containing an organic dye or pigment isformed on the surface (FIG. 3B).

(4) A coating film of an organic dye or pigment or an organic polymerresin containing an organic dye or pigment is formed on a substratesurface, and then one type of degradation-preventing coating film is, ortwo types of degradation-preventing coating film are, formed on thesurface (FIG. 3C).

(5) A coating film containing two types of aqueous liquids of thepresent invention is formed on a substrate surface, and then a coatingfilm of an organic dye or pigment or an organic polymer resin containingan organic dye or pigment is formed on the surface (FIG. 3D).

(B-3) Film Formation Method for Giving BothFading/Discoloration-Preventing Function and Photocatalytic Function

By using an aqueous liquid or dispersion containing a titania-metalcomposite as described in (A) above in one of the undermentioned modes,in the case of forming a coating film having a photocatalytic function(a photocatalytic film) on a substrate, again degradation such as fadingor discoloration of an organic material substrate or a coating film ofan organic dye or pigment formed thereon can be avoided or suppressed.

That is, in the case of making an organic substrate surface have aphotocatalytic function, if a film of a photocatalytic semiconductormetal oxide is formed directly thereon, then chalking is brought about,and hence hitherto a silica compound or amorphous-type titanium peroxidehas been used.

However, a silica compound has organic groups, and amorphous-typetitanium peroxide is converted into anatase-type through sunlight, andhence with an organic substrate surface, chalking is brought about, andthus there has been a problem with durability.

It is thus possible to form an intermediate film using a titania-metalcomposite aqueous liquid or dispersion according to the presentinvention between the organic substrate and the photocatalytic film soas to realize a blocking function of protecting the organic substrate.That is, a titania-metal composite aqueous liquid or dispersionaccording to the present invention has excellent transparency andadhesive film-forming power, and hence degradation of the substrate canbe prevented, and fading can be reduced, and at the same time oxidativedecomposition of the substrate due to the photocatalytic function can beprevented.

The titania of the intermediate film will not exhibit a photocatalyticability even upon being converted into the anatase type throughsunlight. The thickness of the intermediate film is preferably 0.05 to2.0 μm, more preferably 0.1 to 1.0 μm.

There are the following three modes of a film formation method forgiving both a fading/discoloration-preventing function and aphotocatalytic function, and these modes are illustrated in FIG. 4.

(1) A layer of a degradation-preventing coating film is built up on anorganic material substrate surface, and then a photocatalytic film isformed on the surface (FIG. 4A).

(2) A degradation-preventing coating film is formed by being permeatedinto an organic material substrate surface, and then a photocatalyticfilm is formed on the surface (FIG. 4B).

(3) A coating film of an organic dye or pigment is formed on a substratesurface, then a degradation-preventing coating film is built up on thesurface, and then a photocatalytic film is formed on the surface (FIG.4C).

In each of these modes, the degradation-preventing coating film is thusformed between the photocatalytic film and the organic materialsubstrate surface or an organic dye/pigment coating film.

(B-4) Method of Forming Degradation-Preventing Coating Film

There are no particular limitations on layer-building film-forming meansfor forming a degradation-preventing coating film as described above;examples include roll coating, gravure coating, vapor deposition, spincoating, dip coating, bar coating, and spray coating. Moreover, in thecase of forming the degradation-preventing coating film by permeatingin, examples include spray coating and dip coating. After the coatingfilm has been formed, drying is preferably carried out at ambienttemperature or with heating, preferably at a temperature of 60 to 200°C. There are also no particular limitations on the heating means;examples include a constant-temperature dryer and an electromagneticheater.

Regarding the thickness of the coating film formed, the thickness afterdrying is preferably 0.01 to 0.5 μm more preferably 0.1 to 0.2 μm.

(B-5) Object Having Coating Film Formed Thereon

There are no particular limitations on the object on which a coatingfilm is formed using an aqueous liquid or dispersion containing atitania-metal composite according to the present invention, so long asthis object is one that will undergo fading or degradative discolorationthrough ultraviolet radiation or visible light from sunlight, anelectromagnetic radiation generator or the like; examples includecolored coated surfaces, externally installed colored decorativematerials, and organic polymer resins.

For example, as an inorganic substrate, the coating film can beeffectively used on many architectural structures, civil engineeringstructures, constructed objects and machines, for example on glass,metal, ceramic plates such as tiles, stone or concrete, particularly onthe outside. Moreover, as an organic substrate, although timber, paperand so on are also possibilities, the coating film can be effectivelyused in particular on the surface of an organic polymer resin sheet, apainted surface having an organic polymer resin mixed therein, or thesurface of a sprayed material or a plastering material.

More specifically, as a resin sheet, use is possible, for example, onthe surface of a sheet or molded article of a polycarbonate resin, anacrylic resin, a polyester resin, an ABS resin, a vinyl chloride resinor the like.

Moreover, regarding coating materials, the coating film can be usedeffectively on the surface of a so-called paint, plastering material orsprayed material containing a synthetic resin such as an alkyd resin, anacrylic resin, an amino resin, a polyurethane resin, an epoxy resin, asilicone resin, a fluororesin, an acrylic silicone resin, an unsaturatedpolyester resin, an ultraviolet-curable resin, a phenol resin, a vinylchloride resin, or a synthetic resin emulsion. Furthermore, the coatingfilm is also effective on the surface of plastic products, buildingmaterials, vehicles, aircraft, and machinery.

The film thickness in the case of forming the film on such a substrateis preferably 0.01 to 1.0 μm, more preferably 0.05 to 0.3 μm. Moreover,in the case of a coating material having an organic polymer resin or thelike mixed therein, the film thickness is preferably 1.0 to 100 μm, morepreferably 10 to 50 μm.

Moreover, as the film-forming method, all publicly known methods can beused; for example, spray coating, dip coating, flow coating, spincoating, roll coating, brush coating, sponge coating or the like can beused, although to improve physical properties such as the hardness ofthe film formed and the adhesion to the substrate, it is preferable toheat within a permissible heating temperature range for the substrate orcoating material.

(B-6) Mixing into Inorganic Material or Resin Material

A titania-metal composite according to the present invention can be usednot only in a method of forming a film on an organic polymer resinsurface, but can also be mixed into a resin material to obtain a resinsheet, a molded article, a paint, a sprayed material or a plasteringmaterial having similar functional properties.

Resins that can be used include acrylic resins, polyester resins,melamine resins, urea resins, polyamide resins, polyimide resins, epoxyresins, phenol resins, ketone resins, polyurethane resins, siliconeresins, fluororesins, and celluloses. Moreover, these resins may have asubstance such as a silicone, an amine or an epoxy-modified resin addedthereto.

Moreover, a titania-metal composite according to the present inventioncan be added and mixed in during the manufacturing process of any of atile glaze, a hollow iron plate decorative frit or plate glass or glassfibers having an Si compound as a principal component thereof.

The mixing ratio between the inorganic material or resin material andthe titania-metal composite according to the present invention isselected as appropriate according to whether the titania-metal compositeis mixed in as a fine powder or is mixed in as a solution.

(B-7) Applications

Various things as listed below can be given as examples of things towhich an aqueous liquid or dispersion containing a titania-metalcomposite according to the present invention can be applied so as toobtain working effects as described above.

(1) Building materials (interior and exterior materials): Glass, metal,tiles, concrete, coatings, resins, sealing materials, timber, sprayedmaterials, tent fabric, etc.

(2) Equipment: Air conditioners, outdoor air conditioners, coolingtowers, kitchens, sanitary equipment, lighting fixtures, etc.

(3) Glass substrates: Cameras, spectacles, contact lenses, lenses,mirrors, glass tableware, showcases, glass fibers (for cameras), etc.

(4) Automobiles, aircraft, trains: bodies, glass, etc.

(5) Others: Insulators, antistatic substrate surfaces (televisions,glass, acrylic resins, polycarbonate resin sheets, faces, etc.)

(C) Third Invention: Adding Additives, Conferring Anti-SoilingPerformance (C-1) Adding Additives

As described above, a composite between amorphous-type and/oranatase-type titanium oxide which is able to prevent or reducephotooxidative decomposition of organic compounds, and copper,manganese, nickel, cobalt, iron, zinc or a compound thereof is able toprotect an organic substrate from degradation by ultraviolet radiationor the like without having a photocatalytic function, thus improving thedecorativeness of the surface on which the film of the composite isformed; nevertheless, to confer anti-soiling performance whereby soilingis kept off the surface, it is preferable to further add additives toimprove the leveling ability (surface activity) so as to make thesurface on which the film of the composite is formed hydrophilic andthus make formation of the film on a water-repellent substrate easier.

To do this, any of various silicone oils can be used. An alkylsilicateor polyether type can be used, or as a modified silicone oil, apolyether-modified or alkyl-modified type can be used; out of these, apolyether-modified polydimethylsiloxane type paint additive (levelingagent) having a structure that is a composite of the above isparticularly good.

The mixing ratio between the composite of amorphous-type and/oranatase-type titanium oxide and copper, manganese, nickel, cobalt, iron,zinc or a compound thereof, and the additive is preferably in a range of1:0.02 to 1:20, more preferably 1:0.05 to 1:10. Moreover, the titaniumoxide is preferably modified with peroxy groups, i.e. is preferablytitanium peroxide.

When forming a film using a solution of the above, the film thicknessafter drying by heating is preferably approximately 0.01 to 1.0 μm, morepreferably 0.05 to 0.3 μm.

The aqueous liquid or dispersion will not have a photocatalytic abilitytoward glass, metal or a ceramic plate, or an organic substrate such asan acrylic plate, a PP plate or a polycarbonate plate, and hence ananti-soiling coating can be formed with a single coat, without ablocking layer being required. Moreover, as an organic polymer resin orsheet thereof to which the properties of the above invention areconferred, the aqueous liquid or dispersion can be mixed into an organicresin such as an acrylic resin, a polyester resin or a polycarbonateresin.

(C-2) Leveling Agents and Dispersants

By adding a leveling agent or dispersant that makes film formationeasier to the titania-metal composite according to the presentinvention, film formation can be carried out uniformly, and thetitania-metal composite can be dispersed over a substrate uniformly. Assuch a leveling agent or dispersant, a composite of a resin-type, asilicone, a silane compound, a rubber-type silicone, a silicone powder,an organic-modified silicone, a silicone oil or the like is preferable.These utilize the surface activating effect of a silicone polymer, andone having an alkylsilicate structure or a polyether structure, or bothan alkylsilicate structure and a polyether structure in the moleculethereof is preferable.

Here, ‘alkylsilicate structure’ refers to a structure in which alkylgroups are added to silane atoms in the siloxane backbone. Specifically,a substance having siloxane linkages (—Si—O—) as a main chain such aspolydimethylsiloxane is suitable, although there is no limitationthereto.

Moreover, ‘ether structure’ refers to a structure in which alkylenegroups are bonded together by ether linkages such as a polyalkyleneoxide. Specific examples are ones having a structure such aspolyethylene oxide, polypropylene oxide, polytetramethylene oxide, apolyethylene oxide-polypropylene oxide block copolymer, apolyethylene-polytetramethylene glycol copolymer, or apolytetramethylene glycol-polypropylene oxide copolymer. Out of these, apolyethylene oxide-polypropylene oxide block copolymer is particularlysuitable from the viewpoint of being able to control the wettabilitythrough the block degree and the molecular weight, although there is nolimitation thereto.

An organic substance having both an alkylsilicate structure and apolyether structure in the molecule thereof is particularly preferable.Specifically, a polyether-modified polysiloxane type paint additive suchas polyether-modified polydimethylsiloxane can be used; this can bemanufactured using a publicly known method, for example using a methoddescribed in Synthesis Example 1, 2, 3 or 4 in Japanese PatentApplication Laid-open No. H4-242499 or the Reference Example in JapanesePatent Application Laid-open No. H9-165318.

For example, a polyethylene oxide-polypropylene oxide blockcopolymer-modified polydimethylsiloxane obtained by reacting aboth-end-metallyl polyethylene oxide-lene oxide-polypropylene oxideblock copolymer with dihydropolydimethylsiloxane is suitable.

As a leveling agent, TSF4445 or TSF4446 (both made by GE ToshibaSilicones), SH200 (made by Dow Corning Toray Silicone Co., Ltd.), a KPseries one (made by Shin-Etsu Chemical) or the like can be used.

Moreover, as a dispersant, DC3PA or ST869A (both made by Dow CorningToray Silicone Co., Ltd.) or the like can be used. In addition, one thatis not for paints can be used as appropriate so long as the aboveproperties can be conferred.

Moreover, a coating agent type having a silane compound having aminogroups, epoxy groups or methacryloxy groups, i.e. a so-called silanecoupling agent, added thereto can be constructed. Such a coating agentcontains a large amount of Si—O linked matter, and hence the filmhardness and the adhesion to the substrate can be improved.

The mixing ratio (wt %) between the titania-metal composite according tothe present invention and each additive is preferably in a range of1:0.02 to 1:20, more preferably 1:0.05 to 1:10.

(C-3) Effect of Combining Titania-Metal Composite and Additive

With a surface having formed thereon a coating film in which arecombined a titania-metal composite according to the present inventionand an additive comprising a silicone or modified silicone having analkylsilicate structure or a polyether structure or both of thesestructures, a photocatalytic function is not exhibited upon beingsubjected to exciting light, and anti-soiling, anti-microbial ability,gas decomposition and water purification through so-called organiccompound decomposition are not observed. By forming a film using such acoating film liquid, photooxidative degradation of a substrate can thusbe prevented.

On the other hand, by adding an additive as above to a titania-metalcomposite according to the present invention, anti-soiling,anti-microbial and hydrophilic functions that are not photocatalyticorganic decomposition are realized. The present inventors have describedthe working mechanism for this in detail in separately filed JapanesePatent Application No. 2000-374750. That is, it is thought that thisphenomenon does not involve photocatalysis, but rather upon beingsubjected to ultraviolet radiation, sunlight or electromagneticradiation that will bring about photooxidative degradation,anti-soiling, anti-microbial, hydrophilic and anti-rusting functions arerealized in connection with photooxidation that occurs in the organicmaterial or on the surface on which a film has been formed.

That is, a titania-metal composite according to the present invention towhich such an additive has been added not only does not have aphotocatalytic function, but moreover has a function of protectingorganic bonds from molecular bond dissociation energy (photooxidativepower) due to electromagnetic radiation such as ultraviolet radiation,and hence the durability of the film formed is improved, whereby aprotective effect is obtained in that a drop in the lifetime of thesubstrate or a drop in the decorativeness caused by degradation or thelike over a long period is prevented. As a result, with an inorganic ororganic substrate surface having the film formed thereon, substratedegradation and fading are prevented, and anti-soiling, anti-microbial,hydrophilic and anti-rusting functions are exhibited for the surfacehaving the film formed thereon. Regarding the effect of both of thesetypes of function being exhibited, highly effective use is possible withorganic substrates, in particular organic polymer resin substrates andcoating material surfaces.

Hitherto, because organic materials are susceptible to ultravioletradiation, preventing a drop in functionality or decorativeness in termsof commercial value with such substrates has been a great technicalproblem; however, by adding an additive as above to a titania-metalcomposite according to the present invention, an effect that both of theabove types of function are exhibited is obtained, and hence use ispossible for revolutionary inorganic or organic substrates having afunction of resolving problems that have been outstanding for manyyears, for example not only inorganic ones but also organic polymerresin sheets and paints or plastering materials containing organicpolymer resins.

(C-4) Applications

A fields in which this art can be utilized to improve anti-soilingcommercial value is sealing materials, which are the greatest cause ofsoiling of exterior substrates in architecture, civil engineering,constructed objects and so on. Sealing materials are necessities forabsorbing expansion, contraction and displacement due to heating ofexterior substrates and earthquakes, and are used in the joints of themajority of architectural structures, civil engineering structures andconstructed objects.

As such sealing materials, there are silicone types, modified siliconetypes, polysulfide types, polyurethane types, butyl rubber types and soon; the higher the performance of a sealing material in terms of weatherresistance, durability, adhesion and so on, the more surface-chargedmaterial or low-molecular-weight silicone oil due to contamination isdischarged, resulting in being the greatest cause of soiling of exteriorsubstrates. The art of the present invention can also be usedeffectively in such sites.

(C-4-1) First Method

A first method of applying a titania-metal composite aqueous liquid ordispersion having an additive added thereto according to the presentinvention onto a sealing material is a method in which a coatingmaterial to which have been added the titania-metal composite and asilicone or modified silicone solution having an alkylsilicate structureor a polyether structure or both of these structures with a levelingability or dispersing ability (a silane compound may also be added) isapplied directly onto the surface of the sealing material to form afilm.

(C-4-2) Second Method

A second method of applying a titania-metal composite aqueous liquid ordispersion having an additive added thereto according to the presentinvention onto a sealing material is a method in which a coatingmaterial of a film-forming silicone, silane compound or the like is usedas an intermediate film to reduce discharge of contaminants or exposureto charged substances, this being as a primer for a coating material asabove on the sealing material surface.

As a silicone used as the intermediate film, a silicone for aweather-resistant heat-resistant coating material, a reinforcing coatingmaterial or a water-repellant coating material, a silicone for adding toa paint, or the like can be used, so long as this is one that can beused as a silicone coating material. As a commercial product, SR2410 orSE1980 (both made by Dow Corning Toray Silicone Co., Ltd.) or the likecan be used.

Moreover, as a silane compound, one having methoxy groups, ethoxygroups, amino groups, epoxy groups, methacryl groups or methacryloxygroups, and having a silane type oligomer or polysiloxane component canbe used. As a commercial product, Dryseal M or Dryseal W (both made byDow Corning Toray Silicone Co., Ltd.), Aquaseal 200S or 500S (both madeby Sumitomo Seika Chemicals Co., Ltd.) or the like can be used.

The thickness of the intermediate film is preferably 0.05 to 50 μm morepreferably 0.1 to 20 μm. Moreover, as the application method, this iscarried out after filling with a caulking material at the work site, andhence brushing or spraying can be used.

WORKING EXAMPLES

Following is a description of working examples showing the effects ofthe first to third inventions described above, fading/discolorationperformance evaluation tests and so on.

Working Examples 1 Working Examples Relating to Method of ManufacturingTitania-Metal Composite Aqueous Liquids/Dispersions

In these ‘working examples 1’, composites doped with various metals wereprepared by using a method of manufacturing an aqueous liquid ordispersion containing a titania-metal composite according to the presentinvention.

Working Example 1-1 Copper-Doped Amorphous Type

0.463 g of 97% CuCl₂.2H₂O (made by Nihon Kagaku Sangyo Co., Ltd.) wascompletely dissolved in 500 ml of pure water, 10 g of a 50% titaniumtetrachloride solution (made by Sumitomo Sitix) was further added to thesolution, and pure water was added to make up to 1000 ml, whereby asolution was prepared. Ammonia water obtained by diluting 25% ammoniawater (made by Takasugi Pharmaceutical Co., Ltd.) by a factor of 10 wasinstilled into the solution to adjust the pH to 7.0, whereby a mixtureof copper hydroxide and titanium hydroxide was precipitated.

The precipitate was continually washed with pure water until theconductivity of the supernatant was not more than 0.8 mS/m; the washingwas stopped when the conductivity had become 0.8 mS/m, whereupon 340 gof a liquid containing 0.81 wt % of the hydroxide was produced. Next, 25g of 35% hydrogen peroxide (made by Taiki Chemical Industries Co., Ltd.)was added while cooling the liquid to 1 to 5° C., and stirring wascarried out for 16 hours, whereby 365 g of a transparent greendispersion of copper-doped amorphous-type titanium peroxide ofconcentration 0.90 wt % was obtained. This was diluted with pure water,thus preparing 385 g of a 0.85 wt % copper-doped amorphous-type titaniumperoxide dispersion.

Working Example 1-2 Nickel-Doped Amorphous Type

0.594 g of NiCl₂.6H₂O (made by Nihon Kagaku Sangyo Co., Ltd.) wascompletely dissolved in 500 ml of pure water, 10 g of a 50% titaniumtetrachloride solution (made by Sumitomo Sitix) was further added to thesolution, and pure water was added to make up to 1000 ml, whereby asolution was prepared. Ammonia water obtained by diluting 25% ammoniawater (made by Takasugi Pharmaceutical Co., Ltd.) by a factor of 10 wasinstilled into the solution to adjust the pH to 7.0, whereby a mixtureof nickel hydroxide and titanium hydroxide was precipitated.

The precipitate was continually washed with pure water until theconductivity of the supernatant was not more than 0.8 mS/m; the washingwas stopped when the conductivity had become 0.65 mS/m, whereupon 343 gof a liquid containing 0.77 wt % of the hydroxide was produced. Next, 25g of 35% hydrogen peroxide (made by Taiki Chemical Industries Co., Ltd.)was added while cooling the liquid to 1 to 5° C., and stirring wascarried out for 16 hours, whereby 374 g of a transparent pale yellowdispersion of nickel-doped amorphous-type titanium peroxide ofconcentration 0.87 wt % was obtained. This was diluted with pure water,thus preparing 381 g of a 0.85 wt % nickel-doped amorphous-type titaniumperoxide dispersion.

Working Example 1-3 Cobalt-Doped Amorphous Type

0.626 g of CoCl₂.6H₂O (made by Kanto Kagaku) was completely dissolved in500 ml of pure water, 10 g of a 50% titanium tetrachloride solution(made by Sumitomo Sitix) was further added to the solution, and purewater was added to make up to 1000 ml, whereby a solution was prepared.Ammonia water obtained by diluting 25% ammonia water (made by TakasugiPharmaceutical Co., Ltd.) by a factor of 10 was instilled into thesolution to adjust the pH to 7.0, whereby a mixture of cobalt hydroxideand titanium hydroxide was precipitated.

The precipitate was continually washed with pure water until theconductivity of the supernatant was not more than 0.8 mS/m; the washingwas stopped when the conductivity had become 0.68 mS/m, whereupon 341 gof a liquid containing 0.72 wt % of the hydroxide was produced. Next, 25g of 35% hydrogen peroxide (made by Taiki Chemical Industries Co., Ltd.)was added while cooling the liquid to 1 to 5° C., and stirring wascarried out for 16 hours, whereby 364 g of a semi-transparent dark greendispersion of cobalt-doped amorphous-type titanium peroxide ofconcentration 0.85 wt % was obtained.

Working Example 1-4 Manganese-Doped Amorphous Type

0.521 g of MnCl₂.4H₂O (made by Komune Kagaku Yakuhin) was completelydissolved in 500 ml of pure water, 10 g of a 50% titanium tetrachloridesolution (made by Sumitomo Sitix) was further added to the solution, andpure water was added to make up to 1000 ml, whereby a solution wasprepared. Ammonia water obtained by diluting 25% ammonia water (made byTakasugi Pharmaceutical Co., Ltd.) by a factor of 10 was instilled intothe solution to adjust the pH to 7.0, whereby a mixture of manganesehydroxide and titanium hydroxide was precipitated.

The precipitate was continually washed with pure water until theconductivity of the supernatant was not more than 0.8 mS/m; the washingwas stopped when the conductivity had become 0.65 mS/m, whereupon 343 gof a liquid containing 0.77 wt % of the hydroxide was produced. Next, 25g of 35% hydrogen peroxide (made by Taiki Chemical Industries Co., Ltd.)was added while cooling the liquid to 1 to 5° C., and stirring wascarried out for 16 hours, whereby 367 g of a semi-transparent dark browndispersion of manganese-doped amorphous-type titanium peroxide ofconcentration 0.87 wt % was obtained. This was diluted with pure water,thus preparing 375 g of a 0.85 wt % manganese-doped amorphous-typetitanium peroxide dispersion.

Working Example 1-5 Iron-Doped Amorphous Type

0.712 g of FeCl₃.6H₂O was completely dissolved in 500 ml of pure water,10 g of a 50% titanium tetrachloride solution (made by Sumitomo Sitix)was further added to the solution, and pure water was added to make upto 1000 ml, whereby a solution was prepared. Ammonia water obtained bydiluting 25% ammonia water (made by Takasugi Pharmaceutical Co., Ltd.)by a factor of 10 was instilled into the solution to adjust the pH to7.0, whereby a mixture of iron hydroxide and titanium hydroxide wasprecipitated. The precipitate was continually washed with pure wateruntil the conductivity of the supernatant was not more than 0.8 mS/m;the washing was stopped when the conductivity had become 0.744 mS/m,whereupon 420 g of a liquid containing 0.47 wt % of the hydroxide wasproduced.

Next, 25 g of 35% hydrogen peroxide (made by Taiki Chemical IndustriesCo., Ltd.) was added while cooling the liquid to 1 to 5° C., andstirring was carried out for 16 hours, whereby 440 g of a transparentdark yellow/brown dispersion of iron-doped amorphous-type titaniumperoxide of concentration 0.44 wt % was obtained. This was concentratedusing an ultrafiltration concentrator, thus preparing 220 g of thedispersion with the concentration adjusted to 0.85 wt %.

Working Example 1-6 Zinc-Doped Amorphous Type

0.359 g of ZnCl₂ (zinc chloride) was completely dissolved in 500 g ofpure water, 10 g of a 50% titanium tetrachloride solution (made bySumitomo Sitix) was further added to the solution, and pure water wasadded to make up to 1000 g, whereby a solution was prepared. Ammoniawater obtained by diluting 25% ammonia water (made by TakasugiPharmaceutical Co., Ltd.) by a factor of 10 was instilled into thesolution to adjust the pH to 7.0, whereby a mixture of zinc hydroxideand titanium hydroxide was precipitated. The precipitate was continuallywashed with pure water until the conductivity of the supernatant was notmore than 0.8 mS/m; the washing was stopped when the conductivity hadbecome 0.713 mS/m, whereupon 409 g of 0.48 wt % of the hydroxide wasproduced.

Next, 25 g of 35% hydrogen peroxide aqueous solution (made by TaikiChemical Industries Co., Ltd.) was added while cooling to 1 to 5° C.,and stirring was carried out for 16 hours, whereby 430 g of atransparent yellow/brown zinc-doped amorphous-type titanium peroxideaqueous solution was obtained.

Moreover, 100 g of the zinc-doped amorphous-type titanium peroxideaqueous solution produced as above was weighed out, and was heated for 5hours at 100° C., whereupon 48 g of a pale yellow zinc-dopedanatase-type titanium peroxide sol with a concentration of 0.96 wt % wasobtained.

Working Examples 1′-1 to 1′-5

The metal-doped amorphous-type titanium peroxide dispersions prepared inworking examples 1-1 to 1-5 were heated for 5 hours at 100° C., thusproducing corresponding anatase-type titanium peroxide dispersions,which were taken as working examples 1′-1 to 1′-5.

Working Examples 2 Application onto 0 Carbonate Resin Plate

In these ‘working examples 2’, the working examples 1-1 to 1-5 preparedin ‘working examples 1’ above were applied onto polycarbonate resinplates, and the evaluation test described below was carried out.

That is, a 6 mm-thick 70 mm×150 mm commercially sold polycarbonate resinplate (made by Teijin Chemicals Ltd.) was prepared, soiling on thesurface thereof was removed with alcohol, and the aqueous liquid of oneof working examples 1-1 to 1-5 was sprayed onto this substrate with anapplication amount of 0.4 g/100 cm². After the application, the surfacewas dried, and then heating was carried out for 15 minutes at 120° C.using a constant-temperature dryer. Structures of working examples 2-1to 2-5 were thus manufactured. These structures were taken as samplesubstrates 1 to 5. Moreover, for comparison, a 6 mm-thick 70 mm×150 mmcommercially sold polycarbonate resin plate (made by Teij in ChemicalsLtd.) having no coating formed thereon was prepared, and this was takenas comparative substrate 1.

[Evaluation Test 1]

Sample substrates 1 to 5 and comparative substrate 1 were each put intoa Sunshine Weathermeter accelerated weathering test apparatus using anarc carbon lamp, and the state of yellowing of the resin and degradationof the substrate surface through visible light including ultravioletradiation was measured. The testing time was made to be 1000 hours, 2000hours or 3000 hours.

(Evaluation Method and Evaluation Criteria)

The evaluation was carried out by eye. Observation and evaluation werecarried out based on the following evaluation criteria.

+++: Severe yellowing++: Considerable yellowing+: Slight yellowing−: Hardly any yellowing

(Test Results)

The results of ‘evaluation test 1’ are as shown in Table 1.

As is clear from Table 1, it was found that the weather resistance todegradation (yellowing) of the resin through electromagnetic radiationincluding ultraviolet radiation for the polycarbonate resin (organicpolymer resin) plates dropped in the order sample substrates 1 and4>sample substrates 3 and 5>sample substrate 2. On the other hand, itwas found that comparative substrate 1, on which a coating film of anaqueous liquid containing a titania-metal composite according to thepresent invention was not formed, had much lower weather resistance thansample substrates 1 to 5.

Moreover, a similar evaluation test was carried out on substratesmanufactured using each of the metal-doped anatase-type rather thanamorphous-type titanium peroxide dispersions, whereupon similar resultswere obtained, with no photocatalytic function being exhibited.

TABLE 1 Sample Sample Sample sub- sub- sub- Sample Sample Comparativestrate 1 strate 2 strate 3 substrate 4 substrate 5 substrate 1 1,000 − −− − − ++ hours 2,000 − + − − − +++ hours 3,000 − + + − + +++ hours

Working Examples 3 Application onto Tiles

In these ‘working examples 3’, the working examples 1-1 to 1-5 preparedin ‘working examples 1’ above were applied onto white interiordecoration tiles, and the evaluation test described below was carriedout.

That is, a 4 mm-thick 97 mm×97 mm white interior decoration tile (madeby Danto Corporation) was prepared, organic matter on the surface wasremoved by calcining at 500° C. in advance, and then the aqueous liquidof one of working examples 1-1 to 1-5 containing amorphous-type titaniumperoxide was sprayed onto the tile with an application amount of 0.4g/100 cm². After the application, drying was carried out by heating for15 minutes at 80° C., and then an organic dye aqueous solution obtainedby diluting a commercially sold red ink (made by Pilot) by a factor of20 with pure water was applied uniformly onto each tile with anapplication amount of 0.2 g/100 cm², and drying was carried out atambient temperature. Structures of working examples 3-1 to 3-5 were thusmanufactured. These structures ere taken as sample substrates 6 to 10.Moreover, for comparison, the same ti le as for working examples 3 wasprepared, this tile was calcined at 500° C. to remove organic matter onthe surface, and the organic dye aqueous solution was applied on anddrying was carried out at ambient temperature as for working examples 3;this was taken as comparative substrate 2.

Working Examples 3′

The same white interior decoration tiles as for working examples 3 wereprepared, and processing was carried out as for working examples 3,except that the aqueous liquids applied on were made to be the aqueousliquids of working examples 1′-1 to l′-5 containing anatase-typetitanium peroxide. Structures of working examples 3′-1 to 3′-5 were thusmanufactured. These structures were taken as sample substrates 6′ to10′.

Moreover, for comparison, a comparative substrate 2′ as in the case ofworking examples 3 was prepared. This was prepared as for workingexamples 3′, except that an aqueous liquid containing anatase-typetitanium peroxide not doped with a metal was used.

[Evaluation Test 2]

Sample substrates 6 to 10 and comparative substrate 2, and samplesubstrates 6′ to 10′ and comparative substrate 2′ were each placed undera 15 W black light (made by National) with a 10 cm gap and irradiatedfor 155 hours, thus carrying out a fading evaluation using ultravioletradiation (400 nm or less) (ultraviolet radiation intensity 360 nm, 1200μm/cm²).

Furthermore, for sample substrates 6 and 7 and comparative substrate 2,a similar evaluation was carried out, irradiating with direct sunlightfor 5 hours in Kyushu.

(Evaluation Method and Evaluation Results)

Fading of the organic dye was evaluated using a colorimeter (MinoltaCR-200). For the evaluation, the color difference between before andafter the irradiation was measured, the color persistence of eachsubstrate was measured, and bar charts were produced. The measurementresults are shown in FIG. 5 for sample substrates 6 to 10 andcomparative substrate 2.

According to these results, it was found that the color persistencedrops in the order sample substrate 6>sample substrate 10>samplesubstrate 9>sample substrate 7>sample substrate 8. Furthermore, it wasfound that the test results also showed a similar trend under sunlight.

Moreover, the measurement results are shown in FIG. 6 for samplesubstrates 6′ to 10′ and comparative substrate 2′. According to theseresults, it can be seen that in the case of using aqueous liquidscontaining anatase-type titanium peroxide, a similar trend to the caseof using amorphous-type aqueous liquids is shown, but the degradationprevention performance is better.

Working examples 4 Application onto White Tiles in Layers

In these ‘working examples 4’, the working examples 1-1 to 1-5 preparedin ‘working examples 1’ above were applied onto white interiordecoration tiles in layers, and the evaluation test described below wascarried out.

Working Example 4-1

A 4 mm-thick 97 mm×97 mm white interior decoration tile (made by DantoCorporation) was prepared, organic matter on the surface was removed bycalcining at 500° C. in advance, and then a first layer of the aqueousliquid of working example 1-1 with an application amount of 0.2 g/100cm², and a second layer of the aqueous liquid of working example 1-2with an application amount of 0.2 g/100 cm² were sprayed onto the tile.After the application, drying was carried out at ambient temperature,and then an organic dye aqueous solution obtained by diluting acommercially sold red ink (made by Pilot) by a factor of 20 with purewater was applied on uniformly with an application amount of 0.2 g/100cm², and drying was carried out at ambient temperature, thusmanufacturing a structure of working example 4-1. This was taken assample substrate 11.

Working Example 4-2

The aqueous liquids for the first layer and the second layer of thestructure of working example 4-1, i.e. sample substrate 11, were appliedon in the reverse order, and then the organic dye aqueous solution wasapplied on uniformly and drying was carried out at ambient temperatureas for working example 4-1 thus manufacturing a structure of workingexample 4-2. This was taken as sample substrate 12.

Working Example 4-3

Using the same tile and manufacturing procedure as for working example4-1, 50 g of the aqueous liquid of working example 1-1 and 50 g of theaqueous liquid of working example 1-4 were mixed together, and themixture was sprayed onto the tile with an application amount of 0.4g/100 cm². After the application, drying was carried out at ambienttemperature, and then the organic dye aqueous solution was applied on asfor working example 4-1, thus manufacturing a structure of workingexample 4-3. This was taken as sample substrate 13.

Working Example 4-4

Using the same tile and manufacturing procedure as for working example4-1, 10% of the same organic dye aqueous solution as for working example4-1 was mixed into 100 g of an aqueous liquid obtained by mixing 50 g ofthe aqueous liquid of working example 1-1 and 50 g of the aqueous liquidof working example 1-4 together, the mixture was applied on with anapplication amount of 0.4 g/100 and drying was carried out at ambienttemperature, thus manufacturing a structure of working example 4-4. Thiswas taken as sample substrate 14.

Working Example 4-5

Using the same tile and manufacturing procedure as for working example4-1, 10% of the same organic dye aqueous solution as for working example4-1 was mixed into 50 g of the aqueous liquid of working example 1-1 themixture was applied on with an application amount of 0.4 g/100 cm², anddrying was carried out at ambient temperature, thus manufacturing astructure of working example 4-5. This was taken as sample substrate 15.

Working Example 4-6

Using the same manufacturing method as for working example 4-5 but withthe aqueous liquid of working example 1-4, a structure of workingexample 4-6 was manufactured. This was taken as sample substrate 16.

(Comparative Substrate 3)

The same tile as for working example 4-1 was prepared, this tile wascalcined at 500° C. to remove organic matter on the surface, the organicdye aqueous solution was applied on with an application amount of 2g/100 cm², and drying was carried out at ambient temperature, thusobtaining comparative substrate 3.

[Evaluation Test 3]

Sample substrates 11 to 16 and comparative substrate 3 were each placedunder a 15 W black light (made by National) with a 10 cm gap andirradiated for 155 hours, thus carrying out a fading evaluation u singultraviolet radiation (400 nm or less) (ultraviolet radiation intensity360 nm, 1200 μm/cm²).

(Evaluation Method and Evaluation Results)

Fading of the organic dye was evaluated using a colorimeter (MinoltaCR-200). As the evaluation method, the color difference between beforeand after the irradiation was measured. The results were as shown inFIG. 7.

According to these results, it was found that with the exception ofsample substrate 15, sample substrates 11 to 16 had a lower fading rateof the red color than the comparative substrate, and hence there was afading prevention effect. Moreover, the order thereof was samplesubstrate 13>sample substrate 12>sample substrate 11>sample substrate16>sample substrate 14>comparative substrate 3, and it was found thatwith the structures of working examples 4, the fading effect of thesample substrates exceeded the double of that of the comparativesubstrate. Moreover, it was found that there is a similar trend undersunlight.

Working Examples 5

Two types of structure were manufactured as follows.

Working Example 5-1

The same tile as for working examples 3 was prepared, organic matter onthe surface was removed by calcining at 500° C. in advance, and then anorganic pigment (polyazo pigment PC-IT1070 made by Sumika Color Co.,Ltd.) was applied onto the tile with an application amount of 0.2 g/100cm² as a first layer and dried, the aqueous liquid of working example1-4 was applied on with an application amount of 0.2 g/100 cm² as asecond layer and dried, and the aqueous liquid of working example 1-1was applied on with an application amount of 0.2 g/100 cm² as a thirdlayer and dried; heating was then carried out for 15 minutes at 100° C.,thus manufacturing a structure of working example 5-1, i.e. samplesubstrate 17.

Working Example 5-2

The same tile as for working examples 3 was prepared, organic matter onthe surface was removed by calcining at 500° C. in advance, and then anaqueous liquid obtained by mixing the aqueous liquid of working example1-1 and the aqueous liquid of working example 1-4 together in a ratio of1:1 was applied onto the tile with an application amount of 0.2 g/100cm² as a first layer and dried, and an organic pigment (polyazo pigmentPC-IT1070 made by Sumika Color Co., Ltd.) was applied onto the tile withan application amount of 0.2 g/100 cm² as a second layer and dried;heating was then carried out for 15 minutes at 100° C., thusmanufacturing a structure of working example 5-2, i.e. sample substrate18.

[Evaluation Test 4] (Evaluation Method and Evaluation Results)

In this evaluation test using the organic pigment, evaluation wascarried out as for evaluation test 3, whereupon a similar performance toin the case of using the organic dye was obtained.

Working examples 6

An anatase-type titanium peroxide aqueous dispersion (B50 made bySustainable Titania Technology Inc.) was sprayed with an applicationamount of 0.4 g/100 cm² onto each of sample substrates 1 to 5 andcomparative substrate 1 manufactured in evaluation test 1. After theapplication, drying was carried out by heating for 15 minutes at 150°C., thus manufacturing structures 6-1 to 6-5 of working examples 6, andcomparative substrate 4. The structures 6-1 to 6-5 were taken as samplesubstrates 17 to 21.

[Evaluation Test 5] (Evaluation Method)

In this evaluation test, evaluation was carried out as for evaluationtest 1.

(Evaluation Criteria)

If the photocatalytic function has a direct effect on the resinsubstrate surface, then peeling or clouding of the substrate surfacewill occur through oxidative decomposition; an evaluation was thuscarried out by eye of such changes (a blocking effect).

+++: Clouding and peeling observed++: Severe clouding+: Slight clouding−: No changes

(Evaluation Results)

The results regarding the effect of blocking the photocatalytic functionon the resin substrate surface are shown in Table 2. According to theseresults, it was found that the blocking effect drops in the order samplesubstrates 17 and 20>sample substrate 21>sample substrates 18 and 19.With comparative substrate 4 in which the anatase-type titanium oxidecoating film was formed directly on the resin substrate, there was noblocking performance at all.

TABLE 2 Sample Sample Sample sub- sub- sub- Sample Sample strate stratestrate substrate substrate Comparative 17 18 19 20 21 substrate 4 1,000− − − − − +++ hours 2,000 − + + − − +++ hours 3,000 − + + − + +++ hours

Working examples 7 Film-Forming Solutions, Anti-Soiling Evaluation Test

These ‘working examples 7’ relate to the third invention describedearlier; film-forming solutions prepared by adding a polyether-modifiedsilicone as an additive to each of working examples 1-1 to 1-6 preparedin ‘working examples 1’ were applied onto glass plates and polycarbonateresin plates, and the evaluation test described below was carried out.

Film-Forming Solution Manufacturing Example 1

0.4 wt % of a polyether-modified silicone (SH3746 made by Dow CorningToray Silicone Co., Ltd.) was added to the 0.85 wt % copper-dopedamorphous-type titanium peroxide aqueous dispersion manufactured inworking example 1-1 and the mixture was stirred thoroughly; this wastaken as film-forming solution manufacturing example 1.

Film-Forming Solution Manufacturing Examples 2 to 6

0.4 wt % of the polyether-modified silicone (SH3746 made by Dow CorningToray Silicone Co., Ltd.) was similarly added to each of the metal-dopedamorphous-type titanium peroxide aqueous liquids manufactured in workingexamples 1-2 to 1-6 and in each case the mixture was stirred thoroughlyto obtain a film-forming solution; these examples were takenrespectively as film-forming solution manufacturing examples 2 to 6.

Each of the solutions of film-forming solution manufacturing examples 1to 6 was then brushed twice (estimated film thickness 0.08 μm) onto a 4mm-thick 100 mm×100 mm transparent float glass plate and a 4 mm-thick 70mm×150 mm transparent polycarbonate plate, and drying was carried out atambient temperature. The six glass plates and six polycarbonate plateswere then dried by heating for 15 minutes at 80° C. using aconstant-temperature constant-humidity unit, and the glass plates weretaken as sample substrates 22 to 27 and the polycarbonate plates assample substrates 28 to 33.

Moreover, plates on which a film of an anatase-type titanium peroxidedispersion not doped with a metal was similarly formed were taken ascomparative substrates 5 and 6. With comparative substrate 6, however,film-forming solution manufacturing example 1 was brushed on once as aphotocatalytic decomposition blocking primer layer.

[Evaluation Test 6] Anti-Soiling Function Evaluation Test 1 (EvaluationMethod)

One drop of a commercially sold salad oil (made by Nissin Seiyu) wasdropped in three places onto each of sample substrates 22 to 33, and thesample substrates were exposed outdoors in Saga Prefecture, Kyushu forone month from early July to early August.

(Evaluation Criteria)

The number of days until the salad oil marks on each substrate could nolonger be seen was determined by eye. To determine whether or not therewas a mark, tap water was sprinkled on, and if the surface washydrophilic then the salad oil was taken to have been eliminated.

(Evaluation Results)

The results for the number of days until the hydrophobicity due to thesalad oil disappeared for each of the sample substrates were as shown inTable 3.

TABLE 3 Sample No. 23 > No. 27 > Comparative No. 25 > substrate No. 22>No. 24> substrate 5> No. 26 No. days 10 days → 14 days → 28 days untileliminated

The same evaluation was carried out for sample substrates 28 to 33 andcomparative substrate 6; a similar trend was shown.

Intrinsically, each of the metal-doped titania films does not have aphotocatalytic performance, but rather only comparative substrates 5 and6 have a photocatalytic performance; however, it was found that removalof organic material beyond that through photocatalytic decomposition wasobserved, and hence the metal-doped titanias do have an anti-soilingperformance.

Moreover, even upon leaving the polycarbonate plate of comparativesubstrate 6 for two months, the substrate remained transparent with nochalking. It was thus found that film-forming solution manufacturingexample 1 has a function of blocking the photocatalytic decompositionfunction.

Working examples 8 Anti-Soiling Function Evaluation Test 2

A commercially sold 450 mm×600 mm×2 mm polypropylene craft sheet (foamtype, red: chorine-free) was prepared as a film-forming samplesubstrate, and was divided into three as shown in FIG. 8 to givesections A, B and C.

-   -   Section A film formation: The solution manufactured in        film-forming solution manufacturing example 1 was spray-coated        on to form a 0.16 g/100 cm² film, and drying was carried out at        ambient temperature.    -   Section B film formation: A film as formed as for section A        using the solution manufactured in film-forming solution        manufacturing example 1, and taking this as a first layer, a        second layer of a 0.2 g/100 cm² film was then formed by spraying        on an anatase-type titanium peroxide (B50 made by Sustainable        Titania Technology Inc.) aqueous dispersion, and drying was        carried out at ambient temperature.    -   Section C (control): No film was formed.

Films were formed as above by spraying, drying was carried out atambient temperature, outdoor exposure was commenced, and theanti-soiling performance was evaluated after 1 month and after 2 months.

(Evaluation Method)

As an evaluation of the performance against soiling through rain due toair pollution, the color difference values were evaluated using aMinolta colorimeter (CR-300). The results were as shown in Tables 4 to6.

TABLE 4 Color data at beginning: Jun. 6, 2003 Average color Section L *a * b *

 L

 a

 b A 1st 44.35 50.34 30.27 44.43 50.23 30.15 time 2nd 44.39 50.28 30.25time 3rd 44.55 50.08 29.93 time B 1st 48.69 43.11 21.13 48.69 43.1721.14 time 2nd 48.70 43.19 21.20 time 3rd 48.67 43.22 21.09 time C 1st45.58 48.51 28.46 45.65 48.51 28.39 time 2nd 45.66 48.50 28.36 time 3rd45.70 48.51 28.34 time

TABLE 5 Color data after 1 month: Jul. 6, 2003 Average color Section L *a * b *

 L

 a

 b A 1st 45.02 48.17 28.22 45.16 48.02 27.97 time 2nd 45.26 48.01 27.86time 3rd 45.19 47.87 27.84 time B 1st 48.68 42.73 21.31 48.53 42.8921.48 time 2nd 48.46 42.91 21.55 time 3rd 48.46 43.02 21.57 time C 1st44.36 45.57 27.18 44.33 45.46 27.02 time 2nd 44.21 45.25 26.87 time 3rd44.43 45.55 27.00 time

TABLE 6 Color data after 2 months: Aug. 11, 2003 Average color SectionL * a * b *

 L

 a

 b A 1st 45.75 47.11 26.18 45.78 47.04 26.11 time 2nd 45.82 47.01 26.07time 3rd 45.78 47.01 26.08 time B 1st 48.67 43.12 21.06 48.35 43.4421.39 time 2nd 48.38 43.46 21.39 time 3rd 47.99 43.75 21.73 time C 1st43.54 44.38 26.19 43.61 44.52 26.22 time 2nd 43.62 44.62 26.22 time 3rd43.66 44.55 26.29 time

(Evaluation Results)

ΔL after two months for section A exhibited the closest value to ΔL forsection C on which no film was formed (the control) immediately aftercommencement. This means that section A best maintained the originalbase color. Moreover, regarding the redness value Δa of section C of thered substrate immediately after commencement, Δa of section A after twomonths exhibited the closest value to the value immediately aftercommencement, and hence section A best maintained the original basecolor.

It was thus found that for section A, the state before commencement ofthe evaluation of the sample substrates was best maintained, and hencethe anti-soiling performance worked effectively. Moreover, for sectionB, chalking due to a photocatalytic function did not occur. For sectionB, it was found that film-forming solution manufacturing example 1 ofthe first layer blocks the photocatalytic decomposition function.

INDUSTRIAL APPLICABILITY

A titania-metal composite according to the present invention ischaracterized in that at least one out of copper, manganese, nickel,cobalt, iron, zinc, and compounds thereof coexists with titanium oxidefine particles having peroxy groups; in the case that an aqueous liquidor dispersion containing such a titania-metal composite is used with anorganic material such as a resin or an organic dye, performancedegradation such as discoloration or fading caused by energy thatdissociates molecular bonds in organic compounds from ultravioletradiation or visible light from sunlight, an electromagnetic radiationgenerator or the like can be prevented.

In particular, by using this aqueous liquid or dispersion alone to forma coating film adjacent to a coating film of an organic dye or pigment,or using this aqueous liquid or dispersion to form a coating filmtogether with an organic dye or pigment, a drop in decorativeness ofcolor due to fading or discoloration of a coating material, a printedarticle, a building material, a fiber, an organic polymer resin productor the like can be avoided.

Furthermore, because such an aqueous liquid or dispersion containing atitania-metal composite according to the present invention containstitania having peroxy groups, a film thereof can be formed on any ofvarious substrates, regardless of whether organic or inorganic; in thecase of using with a substrate having a substrate property such ashydrophobicity or water-repellency, i.e. an incompatibility with theproperties of water, by adding an alcohol, a surfactant, or a coatingmaterial leveling agent to the dispersion, film formation becomes easy,and moreover a surface performance with anti-soiling, anti-microbial,anti-algal, anti-rusting and hydrophilic functions can be obtained.

1-20. (canceled)
 21. A titania-metal composite dispersion not having aphotocatalytic activity, comprising a mixture of titanium oxide fineparticles doped only with elemental particles, wherein the elementalparticles are formed from an element selected from the group consistingof copper, manganese, nickel, cobalt, iron, and zinc.
 22. Atitania-metal composite dispersion not having a photocatalytic activity,comprising a mixture of titanium oxide fine particles doped only withelemental particles, wherein the elemental particles are formed from anelement selected from the group consisting of copper, manganese, nickel,cobalt, iron, and zinc, and a prescribed additive.
 23. The titania-metalcomposite dispersion not having a photocatalytic activity according toclaim 22, characterized in that said additive is a silicone oil of asilicone or a modified silicone having an alkylsilicate structure and/ora polyether structure.
 24. The titania-metal composite dispersion nothaving a photocatalytic activity according to claim 21, characterized inthat a solvent of the titania-metal composite dispersion not having aphotocatalytic activity comprises water and/or an alcohol.